Mahajan S, Hou J, Sweet A M, Schwartz S A
Department of Medicine, State University of New York at Buffalo, Buffalo General Hospital, NY 14203, USA.
Cell Mol Biol (Noisy-le-grand). 2000 Nov;46(7):1227-38.
Both quantitative and qualitative defects in immune functions in patients with AIDS may result from induction of programmed cell death or apoptosis of CD4 T lymphocytes. We postulate that neurohormones may interact with gp-120 that is shed during active HIV infection and cause apoptosis of immunocompetent cells leading to immunopathogenesis of HIV infections. In this study, we investigated the synergistic effect of cortisol plus HIV gp-120 in inducing apoptosis of lymphocytes from normal subjects. Total peripheral blood mononuclear cells and isolated CD4+ T-cells were treated with cortisol or gp-120 separately and in combination and RNA and DNA were extracted. RNA was reverse transcribed and amplified with specific primers for Fas and Fas ligand and analyzed on agarose gels. DNA was analyzed by gel electrophoresis for ladder formation, the hallmark for apoptosis, and Fas antigen expression by confocal microscopy. Results demonstrate that cortisol and gp-120 induce apoptosis of lymphocytes from normal donors as demonstrated by DNA ladder formation, TUNEL staining and Fas gene expression. Concentrations of cortisol and gp-120 that did not produce apoptosis when used separately, induced significant apoptosis when used in combination. Further, gp-120 induced DNA fragmentation was significant in the CD4+ T-cell subpopulation compared to the CD47 subpopulation. This study suggests that the stress-associated neurohormone, cortisol, synergizes with HIV peptides in causing apoptosis of normal lymphocytes. The synergistic effect of cortisol and gp- 120 in inducing apoptosis of lymphocytes is consistent with a model proposing that stress-associated and circulating HIV-1 derived soluble products may cause progression of HIV infections.
艾滋病患者免疫功能的定量和定性缺陷可能是由程序性细胞死亡或CD4 T淋巴细胞凋亡所致。我们推测神经激素可能与活跃HIV感染期间释放的gp-120相互作用，导致免疫活性细胞凋亡，进而引发HIV感染的免疫发病机制。在本研究中，我们调查了皮质醇加HIV gp-120对诱导正常受试者淋巴细胞凋亡的协同作用。将外周血单个核细胞和分离出的CD4+ T细胞分别用皮质醇或gp-120单独处理及联合处理，然后提取RNA和DNA。RNA经逆转录并用Fas和Fas配体的特异性引物进行扩增，随后在琼脂糖凝胶上进行分析。通过凝胶电泳分析DNA以检测梯状条带形成（凋亡的标志），并通过共聚焦显微镜检测Fas抗原表达。结果表明，DNA梯状条带形成、TUNEL染色及Fas基因表达均证实皮质醇和gp-120可诱导正常供体淋巴细胞凋亡。单独使用时不引起凋亡的皮质醇和gp-120浓度，联合使用时可诱导显著凋亡。此外，与CD47亚群相比，gp-120诱导的DNA片段化在CD4+ T细胞亚群中更为显著。本研究提示，与应激相关的神经激素皮质醇与HIV肽协同作用，可导致正常淋巴细胞凋亡。皮质醇和gp-120诱导淋巴细胞凋亡的协同作用与一种模型相符，该模型认为与应激相关的及循环中的HIV-1衍生可溶性产物可能导致HIV感染进展。
